A printhead assembly of an inkjet printer typically includes one or more printheads that each have a plurality of inkjets from which drops of ink are ejected towards the recording medium. The inkjets of a printhead receive the ink from an ink supply chamber, or manifold, in the printhead which, in turn, receives ink from a source, such as a melted ink reservoir or an ink cartridge. Each inkjet includes a channel having one end connected to the ink supply manifold. The other end of the ink channel has an orifice, or nozzle, for ejecting drops of ink. The nozzles of the inkjets may be formed in an aperture, or nozzle, plate that has openings corresponding to the nozzles of the ink jets. During operation, drop ejecting signals excite actuators in the inkjets to expel drops of fluid from the inkjet nozzles onto the recording medium. By selectively exciting the actuators of the ink jets to eject drops as the recording medium and/or printhead assembly are moved relative to each other, the deposited drops can be precisely patterned to form particular text and graphic images on the recording medium.
One difficulty faced by inkjet printheads is contamination from dust or paper fibers, dried ink, etc. Inkjet printheads typically require periodic maintenance operations to remove the contamination from the nozzle plate and interior ink pathways of the printheads. Printhead maintenance generally includes purging ink through the ink pathways and nozzles of a print head assembly in order to clear contaminants, air bubbles, dried ink, etc. from the printheads. Some of the purged ink as well as any contamination or debris that has formed on the nozzle plate may collect on the nozzle plate after purging.
Several methods have been developed to remove ink and/or contamination from the nozzle plate of a printhead. One previously known method used an elastomeric or “rubber” wiper blade to wipe away ink and contamination from the nozzle plate of a printhead, similar to the way a squeegee removes fluid from a surface. While elastomeric wiper blades are effective in removing ink and debris from the nozzle plates of printheads, such wipers may require specialized materials and be expensive to manufacture. Because elastomeric wiper blades push the ink off the nozzle plate, the wiper blades may also tend to push ink and possibly debris into the nozzles. Elastomeric wiper blades may also have difficulty complying to the surface of the nozzle plate along the entire length of the nozzle plate. Areas of the nozzle plate where there is non-compliance between the wiper blade and the nozzle plate may not be cleaned adequately leaving behind streaks of ink. Also, the high coefficient of friction between the wiper blade and the nozzle plate can cause a stick-slip movement effect, where the wiper chatters during the wiping process possibly skipping over ink on the nozzle plate.